کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5186639 | 1381109 | 2008 | 10 صفحه PDF | دانلود رایگان |
The tensile and compressive properties of triptycene-polycarbonates were tested over 6 orders of magnitude in strain rate. Initially we studied a low molecular weight, low triptycene content PC blended with Iupilon® PC and then a series of higher molecular weight, higher triptycene content polymers. The PC blend with only 1.9 wt% triptycene displayed up to 20% increase in modulus and up to 17% increase in yield strength with elongations over 80% as compared to the Iupilon® PC. The higher molecular weight T-PCs (up to 26 wt% triptycene) exhibited improvements in modulus by over 20% and improvements in compressive strengths by nearly 50% at both low and high strain rates without any apparent sacrifice to ductility, as compared to Iupilon® PC. All samples containing triptycene units retained transparency and exhibited no signs of crystallinity or phase separation. Moreover, both the blends and triptycene-PC copolymers displayed significantly altered dynamic mechanical spectra, specifically, the emergence of a pronounced, new βⲠrelaxation approximately 75 °C above the traditionally observed β relaxation in PC (approximately â100 °C). The enhancement of the mechanical properties observed provides valuable insights into the unique packing and interactions during plastic flow induced by the presence of triptycene units.
Journal: Polymer - Volume 49, Issue 21, 6 October 2008, Pages 4703-4712